Process for treating artificial casein fibers



Patented Feb. 7, 1939 PATENT O'FFICE PROCESS FOR TREATING ARTIFICIAL CASEIN FIBERS Marino Fortunato, Milan,

Italy, assignor to Montecatini Societa Generale per llndustria Mineraria e Chimica, Milan, Italy, a corporation of Italy No Drawing. 'Application June, 2, 1937, Serial No. 146,123. In Italy June s, 1936 2 Claims.

It is well known that it is possible to produce an artificial fiber similar to natural wool starting from casein. This product will be called herein shortly casein wool. 5 The behaviour of this fiber in dyeing with chrome colours is rather different from that of natural wool especially with respect to shades obtained. This inconvenience is highly deprecated by dyers, as it precludes dyeing the fiber made of a mixture of natural and casein wool,

and, consequently, hinders one form of application of casein wool which otherwise should in practice he the best. It has now been found that if casein wool is subjected to a preliminary treatment with diluted acid solutions, its behaviour with respect to chrome colours becomes analogous to that of natural wool.

The treatment may be carried out on the casein wool fiber as well as directly on the mixed fiber of casein and natural wool.

Example 1.-The mixture of casein and natural wool is treated during minutes with abath containing 1-2 c. c. m.-'phosphoric acid per litre,

25 at 40-50" C. It is washed, then neutralized with edition, 2nd volume, p. 59, and dyeing is started 30 at about C. in the presence of 10% chrystallized sodium sulphate. The bath is slowly brought to the boil and 1-2% acetic acid added. The material is boiled during about 20 minutes and the dyestuff exhausted by 12% formic acid.

The bath is cooled and after addition. of 1% sodium or potassium bichromate it is again brought to boil for about 20-30 minutes. At the end the material is washed.

The preliminary treatment with acid may be a first step of dyeing according to the above exmerit. In either case, on both the fiber of casein casein wool and natural wool tor dyeing with chrome dyes, which comprises ..treating these I mixed fibers with a dilute aqueous solution having an acid reaction due to the presence of phosphoric acid.

MARINO FORTUNATO. 

